EP4139418A1

EP4139418A1 - Method and apparatus for producing hydrocarbons and use

Info

Publication number: EP4139418A1
Application number: EP21721576.3A
Authority: EP
Inventors: Pekka Simell; Muhammad QURESHI; Elmeri PIENIHÄKKINEN
Original assignee: Valtion Teknillinen Tutkimuskeskus
Current assignee: Valtion Teknillinen Tutkimuskeskus
Priority date: 2020-04-20
Filing date: 2021-04-19
Publication date: 2023-03-01
Also published as: WO2021214384A1; US20230212461A1

Abstract

The invention relates to a method and an apparatus for producing hydrocarbons from plastic containing material, wherein the plastic containing material (1) is subjected into a pyrolysis reactor (2), steam (3) is fed into the pyrolysis reactor, and the plastic containing material is pyrolyzed with the steam by using a catalytic pyrolysis with a basic catalyst to convert the plastic containing material to a product (4) comprising hydrocarbons. Further, the invention relates to the use of the product obtained by the method.

Description

METHOD AND APPARATUS FOR PRODUCING HYDROCARBONS AND USE

FIELD

The application relates to a method defined in claim 1 and an apparatus defined in claim 12 for producing hydrocarbons from plastic containing materi al. Further, the application relates to a use of the product obtained by the method defined in claim 17.

BACKGROUND

Known from the prior art is to produce liquid products from different raw materials in a pyrolysis process. The raw materials, e.g. polymer containing materials, can be converted to products by applying a catalytic pyrolysis. The catalytic processes are based on acidic catalysts, like zeolites and related alumi nosilicates. They result in a high amounts of soot (carbon) and relatively low yields and quality of oil products. Further, when the raw material comprises chlorine or bromine the pyrolysis product, such as gas or oil, has to be cleaned from these impurities before utilization of the product.

OBJECTIVE

The objective is to solve the above problems. Further, the objective is to disclose a new type meth od and apparatus for treating plastic containing mate rials and wastes. Further, the objective is to produce desired hydrocarbon product by the pyrolysis. Further, the objective is to improve yield of liquid hydrocar bon product.

SUMMARY

The method and apparatus and use are charac terized by what are presented in the claims. In the method and apparatus, hydrocarbons are produced from plastic containing material by a cata lytic pyrolysis.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying drawing, which is included to provide a further understanding of the invention and constitutes a part of this specification, illus trates some embodiments of the invention and together with the description help to explain the principles of the invention. In the drawing:

Fig. 1 is a flow chart illustration of a pro cess according to one embodiment.

DETAILED DESCRIPTION

In a method for producing hydrocarbons from plastic containing material, the method comprises steps: subjecting the plastic containing material (1) into a pyrolysis reactor (2), feeding steam (3) into the pyrolysis reactor, and pyrolyzing the plastic con taining material with the steam by using a catalytic pyrolysis with a basic catalyst to convert the plastic containing material to a product (4) comprising hydro carbons, such as to a liquid hydrocarbon product.

An apparatus for producing hydrocarbons from plastic containing material comprises a pyrolysis re actor (2) which comprises a basic catalyst and in which the plastic containing material (1) is pyrolyzed with steam by using a catalytic pyrolysis with the basic catalyst to convert the plastic containing mate rial (1) to a product (4) comprising hydrocarbons, such as a liquid hydrocarbon product, and at least one inlet for subjecting the plastic containing material (1) into the pyrolysis reactor (2), and at least one feeding device for feeding the steam (3) into the py rolysis reactor. Some embodiments of the method and the appa ratus are shown in Fig. 1.

In this context, the plastic containing mate rial (1) means any material, recycled material, resi due material or waste material, which contains plas tic, plastic type material, polymers, e.g. plastic type polymers, mixtures of plastics and/or polymers or the like. In one embodiment, the plastic containing material is selected from the group consisting of re cycled plastic containing material, plastic containing waste, plastic containing residue material and their combinations. The plastic containing material can com prise one or more components. The plastic containing material can comprise also other materials than plas tic, polymers or plastic type materials.

In one embodiment, the plastic containing ma terial (1) may comprise polyethylene, polypropylene, PVC, other plastics, other polymer components, or their combinations. In one embodiment, the plastic containing material may comprise impurities. In one embodiment, the plastic containing material comprises impurities including chlorine, bromine and/or sulfur. In one embodiment, the impurities including chlorine, bromine and/or sulfur are captured by the basic cata lyst during the catalytic pyrolysis.

In this context, the product (4) comprising hydrocarbons means any product which is formed by the catalytic pyrolysis with the basic catalyst and which comprises hydrocarbons. In one embodiment, the product (4) comprising hydrocarbons is a liquid hydrocarbon product, such as pyrolysis oil. In one embodiment, py rolysis product is in a gaseous form, such as pyroly sis gas, just after the pyrolysis reactor (2). In one embodiment, the pyrolysis product is at least partly in a liquid form after the pyrolysis reactor (2). In one embodiment, if the pyrolysis product is in the gaseous form, it may be condensed to form the liquid hydrocarbon product after the pyrolysis reactor. Pref erably, the product (4) comprising hydrocarbons com prises at least liquid hydrocarbons. Further, the product may comprise other hydrocarbons, compounds or components, such as gas, wax and/or char. The product comprising hydrocarbons can consist of one or more main components. In one embodiment, the product com prises at least the liquid hydrocarbons and wax. In one embodiment, the product comprises at least the liquid hydrocarbons and gas. In one embodiment, the product comprises at least the liquid hydrocarbons and char. In one embodiment, the product comprises at least the liquid hydrocarbons, gas, wax and char. In one embodiment, the product (4) comprising hydrocar bons is recovered. In one embodiment, the product can contain 40 - 90 % liquid hydrocarbons. In one embodi ment, the liquid hydrocarbon product comprises middle distillates. Alternatively, the liquid hydrocarbon product may comprise other hydrocarbon compounds or fractions.

In one embodiment, the steam (3) is fed from a bottom of the pyrolysis reactor (2). In one appa ratus embodiment, the steam (3) is arranged to be fed via a bottom of the pyrolysis reactor (2) into the py rolysis reactor (2). In one embodiment, the apparatus comprises a distribution device, e.g. plate, plate with holes, grate, baffle or the like, to distribute the steam in the pyrolysis reactor.

In one embodiment, the basic catalyst, e.g. dolomite or other basic material, is fed into the py rolysis reactor. In one embodiment, the basic catalyst is added as a fresh makeup catalyst feed into the py rolysis reactor during the pyrolysis. In one embodi ment, the apparatus comprises at least one catalyst feeding device for feeding the basic catalyst into the pyrolysis reactor. The catalyst feeding device can be selected from any suitable feeding device, feeder or similar device known per se. In one embodiment, the used basic catalyst which flows out from the pyrolysis reactor and/or which is recovered from the pyrolysis reactor is recirculated back to the pyrolysis reactor, e.g. directly or via reforming. In one embodiment, the used basic catalyst is discharged and/or recovered from filters, cyclones or the like, in which solids are separated from the product or product vapors, af ter the pyrolysis reactor. In one embodiment, the basic catalyst is discharged and/or recovered from the bottom of the pyrolysis reactor, e.g. by means of a screw.

In one embodiment, the plastic containing ma terial (1) and the steam (3) are mixed to form a mix ture in the pyrolysis reactor (2). In one embodiment, the plastic containing material (1) and the steam (3) can get mixed in the pyrolysis reactor. It is im portant that the catalytic pyrolysis with the basic catalyst is carried out in presence of the steam.

In one embodiment, temperature is 450 - 700 °C, in one embodiment 450 - 650 °C, in one embodiment 500 - 650 °C, in one embodiment 550 - 650 °C, and in one embodiment 570 - 630 °C, during the catalytic py rolysis in the pyrolysis reactor (2).

In one embodiment, residence time is 0.5 - 3.0 seconds in the catalytic pyrolysis. In one embodi ment, the residence time is 1 or over 1 seconds in the catalytic pyrolysis. In one embodiment, the residence time is 1.0 - 2.8 seconds in the catalytic pyrolysis.

In one embodiment, the pyrolysis reactor (2) is a fluidized bed reactor. In one embodiment, the py rolysis reactor (2) is a bubbling fluidized bed reac tor. In one embodiment, the pyrolysis reactor (2) is a circulating fluidized bed reactor. Alternatively, any suitable pyrolysis reactor can be used.

A fluidizing gas is used in the fluidized bed reactor. In one embodiment, the fluidizing gas is sub jected to the pyrolysis reactor (2). In one embodi ment, the steam (3) is used at least partly as the fluidizing gas. In one embodiment, the fluidizing gas is a composition containing the steam and/or nitrogen. Further, in one embodiment, the fluidizing gas may comprise other components. In one embodiment, nitrogen is used as the fluidizing gas. In one embodiment, the fluidizing gas comprises the steam. In one embodiment, the steam is added to the fluidizing gas. Adding the steam to the fluidizing gas results in improved liquid yield, such as pyrolysis oil yield, and quality. In one embodiment, the fluidizing gas comprises below 50 vol-% steam, in one embodiment 0.1 - 30 vol-%, in one embodiment 10 - 20 vol-% steam. In one embodiment, the fluidizing gas and the steam are subjected separately into the pyrolysis reactor.

In one embodiment, heat to the catalytic py rolysis and/or catalyst bed is provided indirectly by heating the catalyst material and/or steam in another device.

In one embodiment, the basic catalyst is se lected from the group consisting of dolomite, e.g. calcined dolomite, limestone or other basic materials. The basic catalyst can be used as such or as a mixture with sand. In one embodiment, the catalyst of the py rolysis reactor comprises the basic catalyst and sand. The basic catalyst, such as dolomite or limestone, ad sorbs the most common impurities, like halogenides and sulfur, during the catalytic pyrolysis, and then this catalytic pryrolysis process is suitable also for con taminated plastic waste. Further, the basic catalyst acts as a steam reforming catalyst enhancing the reac- tion of gas phase intermediate pyrolysis product and steam, which stops the polymerization of the hydrocar bons and thus also the build up of heavy molecular weight products and soot. In one embodiment, CaO and MgO of the dolomite catalyst act as halogenide and sulfur adsorbents. Preferably, the basic catalyst has following properties in the catalytic pyrolysis in the presence of steam: it depolymerizes by abstracting hy drogen from the polymer, it prevents further re polymerization, and/or it acts as the absorbent.

In one embodiment, the product (4) which com prises hydrocarbons is in the gaseous form (4a) after the pyrolysis reactor (2), and the gaseous product is condensed in a condenser (5) to form the liquid hydro carbon product.

In one embodiment, the inlet for subjecting the plastic containing material (1) into the pyrolysis reactor (2) may be selected from any suitable inlet known per se, e.g. pipe, port or the like. In one em bodiment, the plastic containing material is fed using a screw feeder to the pyrolysis reactor. Alternative ly, any suitable feeder can be used to feed the plas tic containing material to the pyrolysis reactor. In one embodiment, the feeder is selected from a screw feeder, silo feeder, hydraulic feeder, pneumatic feed er, melt feeder and their combinations.

In one embodiment, the feeding device, such as steam feeding device, for feeding the steam into the pyrolysis reactor (2) may be selected from any suitable feeding device, feeder or similar device known per se. In one embodiment, the steam can be sup plied to the pyrolysis reactor by means of a steam generator and pipe. In one embodiment, the steam is fed through a grid.

Further, in one embodiment, the apparatus comprises at least one outlet for discharging the product (4) from the pyrolysis reactor (2). The outlet may be any suitable outlet known per se, e.g. pipe, outlet port or the like.

In one embodiment, the product (4) comprising hydrocarbons, such as liquid hydrocarbon product, can be treated, post-treated or supplied to a next process or a next process step after the catalytic pyrolysis. In one embodiment, the product (4) comprising hydro carbons is treated by the condensation to form the liquid hydrocarbon product. In one embodiment, the product (4) comprising hydrocarbons or the liquid hy drocarbon product is treated by a synthesis or a re finery process to form a final product after the py rolysis reactor.

In one embodiment, the method and apparatus are based on a continuous process. In one embodiment, the method and apparatus can be based on a batch pro cess.

In one embodiment, the method and apparatus can be used to produce the liquid hydrocarbon products for forming middle distillates, fuels, monomers or chemicals, for feed to refinery, polymerization or ma terial manufacturing, or to their combinations.

In one embodiment, the product comprising hy drocarbons, such as the liquid hydrocarbon product, is used as a hydrocarbon component for forming middle distillates, fuels, monomers or chemicals, or as a feed to refinery, polymerization or material manufac turing, or in their combinations.

Thanks to the invention, the high yield of liquid hydrocarbon product can be obtained. Different plastic containing materials can be used as raw mate rial. The catalytic pyrolysis with the basic catalyst is suitable to treat also contaminated plastic waste. Problematic compounds, such as chlorine, bromine and sulfur, can be captured by the basic catalyst materi- al. Further, the products with improved quality can be produced.

The method and apparatus offer a possibility to produce liquid hydrocarbon product from plastic containing materials with good properties easily, and energy- and cost-effectively. The present invention provides an industrially applicable, simple and af fordable way to produce desired pyrolysis oil products from different plastic containing materials. The meth od and apparatus are easy and simple to realize in connection with production processes. Thus, the pre sent invention improves waste plastic recycling.

EXAMPLES

Fig. 1 presents some embodiments of the pro cess for producing hydrocarbons from plastic contain ing material (1).

The apparatus comprises a fluidized bed py rolysis reactor (2) which comprises a basic catalyst, such as dolomite or limestone, and in which the plas tic containing material (1) is pyrolyzed with steam by using a catalytic pyrolysis with the basic catalyst. The plastic containing material comprises at least one plastic or plastic type polymer. Alternatively, the plastic containing material is a mixture of different plastics and/or polymers. The apparatus comprises at least one inlet for subjecting the plastic containing material (1) into the pyrolysis reactor (2), and at least one feeding device for feeding the steam (3) from a bottom of the pyrolysis reactor into the pyrol ysis reactor (2).

In the pyrolysis reactor (2), the plastic containing material and the steam are mixed to form a mixture. The temperature of 450 - 700 °C, e.g. 480 - 550 °C or at at around 500 °C, can be used during the catalytic pyrolysis. Further, the catalyst comprises at least dolomite or limestone, and further the cata lyst may comprise sand. A fluidizing gas is used in the fluidized bed pyrolysis reactor (2). The steam (3) can be used at least partly as the fluidizing gas in the reactor. Alternatively, the fluidizing gas com prises nitrogen and/or oxygen, and the steam is sub jected separately into the pyrolysis reactor. During the pyrolysis the plastic containing material is con verted to a product (4) comprising hydrocarbons. If the product (4) is in the gaseous form (4a), such as pyrolysis gas, the product can be treated by a conden sation (5) for forming a liquid product (4b).

Example 1

In this example, plastic containing material was treated in a fluidized bed pyrolysis reactor which comprises dolomite (D) as a basic catalyst and bed ma terial. The plastic containing material, which com prises polypropylene, was pyrolyzed with steam by us ing a catalytic pyrolysis with the dolomite. In com parative experiments, the pyrolysis was carried out without steam and/or the dolomite.

In this example, nitrogen (N) or a mixture of nitrogen (N) and steam (S) was used as a fluidizing gas. Temperatures were 500°C and 600°C during the cat alytic pyrolysis, and residence times were 1, 2.4 and 2.8 seconds. In comparative experiments, an inert ma terial (I) was used as a bed material.

The process conditions and compositions of the products are presented in Table 1. Table 1

In the table, D is dolomite,

I is inert material,

S is steam, and N is nitrogen.

NChar yield on the bed material is calculated by weighting the bed material before and after the experiment.

From the test it was observed that the plas tic containing material can be converted effectively to liquid hydrocarbons, especially when the mixture of nitrogen and steam was used during the catalytic py rolysis. Further, it was observed that a yield of the liquid hydrocarbons can be increased when the resi- dence time was longer.

The pyrolysis reactor, inlet, feeding devic es, and condenser and other devices and equipments of the process used in Fig. 1 are known per se in the art, and therefore they are not described in any more detail in this context.

The method and apparatus are suitable in dif ferent embodiments for producing hydrocarbons, such liquid hydrocarbon product, from different plastic containing waste materials by means of catalytic py rolysis process.

The invention is not limited merely to the examples referred to above; instead many variations are possible within the scope of the inventive idea defined by the claims.

Claims

1. A method for producing hydrocarbons from plastic containing material, characterized in that the method comprises steps - subjecting the plastic containing material (1) into a pyrolysis reactor (2),

- feeding steam (3) into the pyrolysis reactor, and

- pyrolyzing the plastic containing material with the steam by using a catalytic pyrolysis with a basic catalyst to convert the plastic containing material to a product (4) comprising hydrocar bons.

2. The method according to claim 1, char acterized in that the product (4) comprising hy- drocarbons is a liquid hydrocarbon product.

3. The method according to claim 2, char acterized in that the liquid hydrocarbon prod uct comprises middle distillates.

4. The method according to any one of claims 1 to 3, characterized in that the steam (3) is fed from a bottom of the pyrolysis reactor (2).

5. The method according to any one of claims 1 to 4, characterized in that the basic cata lyst is added as a fresh makeup catalyst feed into the pyrolysis reactor during the pyrolysis.

6. The method according to any one of claims 1 to 5, characterized in that the plastic containing material (1) and the steam (3) are mixed to form a mixture in the pyrolysis reactor (2).

7. The method according to any one of claims

1 to 6, characterized in that temperature is 450 - 650 °C during the catalytic pyrolysis in the py rolysis reactor (2).

8. The method according to any one of claims 1 to 7, characterized in that the pyrolysis reactor (2) is a fluidized bed reactor.

9. The method according to any one of claims 1 to 8, characterized in that the steam (3) is used at least partly as a fluidizing gas.

10. The method according to any one of claims 1 to 9, characterized in that the basic cata lyst is selected from the group consisting of dolo mite, limestone or other basic materials.

11. The method according to any one of claims 1 to 10, characterized in that the product which comprises hydrocarbons is in the gaseous form after the pyrolysis reactor (2), and the gaseous prod uct is condensed in a condenser (5) to form the liquid hydrocarbon product.

12. An apparatus for producing hydrocarbons from plastic containing material, character ized in that the apparatus comprises

- a pyrolysis reactor (2) which comprises a basic catalyst and in which the plastic containing ma terial (1) is pyrolyzed with steam by using a catalytic pyrolysis with the basic catalyst to convert the plastic containing material (1) to a product (4) comprising hydrocarbons,

- at least one inlet for subjecting the plastic containing material (1) into the pyrolysis reac tor (2), and

- at least one feeding device for feeding the steam (3) into the pyrolysis reactor (2).

13. The apparatus according to claim 12, characterized in that the steam (3) is ar ranged to be fed via a bottom of the pyrolysis reactor (2) into the pyrolysis reactor (2).

14. The apparatus according to claim 12 or 13, characterized in that the apparatus com prises at least one mixing equipment to mix the plas tic containing material (1) and the steam (3) for forming a mixture in the pyrolysis reactor (2).

15. The apparatus according to any one of claims 12 to 14, characterized in that the pyrolysis reactor (2) is a fluidized bed reactor.

16. The apparatus according to any one of claims 12 to 15, characterized in that the basic catalyst is selected from the group consisting of dolomite, limestone or other basic materials.

17. A use of the product comprising hydrocar bons obtained by the method according to any one of claims 1 to 11, characterized in that the product (4) comprising hydrocarbons is used as a hy drocarbon component for forming middle distillates, fuels, monomers or chemicals, or as a feed to refin ery, polymerization or material manufacturing, or in their combinations.